What is the definition of earthing and how it works?
It is a step up or step down for power delivery.
An audio frequency transformer is a transformer designed to operate in the range of frequencies audible to the average human. This range is generally accepted to be from 20 Hz to 20,000 Hz. The usual purpose of an audio transformer is to match impedances between circuit sections. For example: between a microphone and the input of an amplifier, (input transformer), or between the output of an amplifier and the loud speaker. (output transformer).
Without a load the secondary current is zero, by definition.
A transformer is a transformer, for the most part. The use of "industrial" here may just mean the transformer in question is constructed a little more robustly than a "regular" transformer. One generalization about transformers is that they are generally built pretty tough 'cause they are usually a bit more expensive to construct than most basic components and the manufacturer doesn't want it to fail. But the "industrial" version may be even tougher to withstand more punishment because of the application.
a hole transformer
Transformer has windings
The Load will consume part of the power and therefore reduce the current (voltage ) available for the secondary part of the transformerAnswerYou cannot apply a load to the primary of a transformer which, by definition, is the winding connected to the supply voltage. Your question makes no sense.
yes we can place auto transformer in place of original transformer
Transformer is by definition can transform only AC current. But it's possible to build device that can step up or step down DC voltage directly. These are called DC-DC converters not transformers.
In power transformer, a differential relay is a relay that verifies the balance of current between the primary and the secondary face of a transformer. It is also employed in other components of the power system like in protecting cables. Differential relay is also called a unit protection.
A transformer that increases voltage is a step-up transformer.